The story is filled with modern scientific techniques, a sense of wonder, and is also a relevant cautionary tale about the damage being done to the ecosystem and the diversity of life on Earth. A passionate billionaire scientist, Dr. Alex Pierce, and the intelligent and beautiful activist, Cassie Worth, have devoted their lives to recreating the lost past and protecting the future. They collect and maintain an ambitious “Library of Earth” to store the genetic information of currently endangered species in hopes of preserving much of Nature’s wealth before it becomes extinct. As part of this work, Alex and Cassie use restored DNA taken from museums and preserved specimens to bring back wondrous extinct animals that have been eradicated through the callous mistakes of mankind—passenger pigeons, Tasmanian tigers, dodos. On a vast ranch in the wilds of Alaska, they have recreated an environment from the end of the last Ice Age, complete with dire wolves, sabretooth tigers, and a herd of woolly mammoths.